Method of making gin ribs



Dec. 4, 1934. o. MITCHELL METHOD OF MAKING GIN RIBS Filed Nov.` 23,'1931 Dec. 4, 1934.

o. MITCHELL METHOD OF MAKING GIN RIBS Filed Nov. 25, 1931 2Sheets-SheetZ Patented Dec. 4,

UNITED STATES PATENT OFFICEy Claims.

The general object of this invention is to provide a no-vel method ofproducing gin ribs in which a group of parallel ribs are cast integral,i with supports at their upper and lower extremi- 51ties and providedwith interposed saw spaces of exact and uniform width and equi-distantfrom each other.

Prior to my invention, attempts have been made to form gin ribs frompressed steel in groups.

A Such ribs, however, have never been found practicable and, so far asmy knowledge extends, are not used, the main reason accounting for theirnon-use being that the space between the gin -saws is so restricted thatit has been found iml'possible to provide sufcient strength or rigidityin a rib formed from sheet metal. Another dill-lculty has been that ribsat the ginning point, that is,vthat part of the space between the ribsthrough which the cotton is carried by the saws, must be g''very hard towithstand the action gf the sand carried through with the cotton, andonly chilled iron has thus far met this requirement.

Up to the present time, therefore, the ribs for gins have been made andmounted separately.

To expedite foundry work, in some instances the ribs have been cast ingroups with thin Weak points of metal between the ribs, and afterwardsbroken apart at the weak points and ground on l each side, so as to formfairly accurate or uniform vspaces at the ginning points of the ribswhen the latter were secured in position in the gin.

The major portion of the ordinary gin rib, below the ginning `point ofthe rib; is made narrow enough so that when the ribs are secured inplace in parallel relation they will provide comparatively wide spacesfor the lower portion of the gin saws to Awork through, and this portionof the rib does not necessarily have to be uniform or of any definitewidth. The upper portion of each rib, ohoweven is provided with aginning surface exposed to the roll box. This surface is somewhat widerthan the lower portion of the rib, and is ordinarily produced by arelatively thin flange which projects from each side of the ginning 15.portion of the rib. It is these thin flanges or extensions, that areground olf on each side of the ordinary rib to form the spaces at theginning point through which the saws revolve, as ex-- plained above.

In order to have the gin saws carry the cotton through the spacesbetween the ribs at the ginning point as freely as possible and with theminimum cutting` action on the lint, it is important to have the ginningspaces in which the saws -run as wide as practicable, but at the sametime ycast integral at theirlower ends.

(Cl. 25J-163.5)

it is just as important to prevent seeds, and particles of seed, beingcarried by the gin saws through the spaces with the lint. To this end,it is essential to have the working spaces for the saws very uniform,and this is not possible inthe use of individual ribs independentlysecured to the gin rails. This is due to the fact that theV work is doneby hand, the ribs being generally screwed at opposite ends to supportingrails, and if a rib is placed slightly out of position or alignment, itwill cause the space between it and the next rib to be too narrow on oneside and correspondingly too wide on the opposite side.

All of these difficulties are overcome by my invention, which securesthe provision of sawl spaces between the ribs of absolutely uniformwidth and equally accurate spacing of the ribs from each other.

The invention is illustrated in the accompanying drawings, in which:-

Figure 1 is a front View of a cast group of ribs before having the sawspaces machined therein;

Figure 2 is also a front view of the casting, but showing a grindingimplement applied thereto in the process of simultaneously forming sawspaces between the upper portions of the ribs;

Figure 3 is a sectional view taken on the line 3 -3 of Figure 2;

Figure 4 is a cross sectional view taken through a set of gin ribssecured in position and showing the relation rthereto to the gin saws;and

Figure 5 is aV face View on an enlarged scale of a portion of a completegroup of ribs, showing the saw spaces above the ginning points taperedout-k wardly and upwardly.

Referring now to the drawings, the numeral 1 indicates a castingproviding a group of ribs, 2, The ribs 2 are of the conventional curvedshape shown by Figure 3, and in the upperportion of .the casting theseribs are united by relatively thin, interposed webs 4, and are vcastintegral with a support, 5. The ribs 2 of the casting are sufficientlynarrow to provide between them relatively wide spaces 6, through whichthe lower portion of the gin saws project, as shown by Figure 4. In itsupper portion, each rib is provided with a ginning surface exposed tothe roll box which is somewhat wider than the lower portionof the ginrib, and this extended surfaceis usually formed by relatively thinflanges, 7, projecting laterally from either side of the rib in itsupper portion, the inner surface of said webs being iiush with the innersurface of the body of. said ribs. By inner surface, I refer to thesurface exposed to the roll box. The o-pposed edges of these flangesdei-lne the size of working spaces, 9, for the saws of the gin, whichspaces are much narrower than the spaces 6. In practice, they are wideenough to permit the gin saws 8 to pass freely through them, and narrowenough to prevent seeds or par ticles of seed being carried by the ginsaws through these spaces with the lint. It is of the utmost importancethat these spaces, 9, should be positioned equi-distant from each otherand that the spacing should exactly correspond to the spacing of thesaws 8 o-f the gin. It is also necessary that the spaces 9 should be ofuniform width at the points where the saws pass through them, asotherwise lack of uniformity in these respects will result in somespaces being so narrow as to cause cutting of the lint, while otherspaces will be wide enough to permit particles of seed and other foreignmatter being carried through by the saws with the lint. This, as I haveheretofore explained, is a disadvantage incident to all gins as nowconstructed.

According to my invention, I provide the working spaces 9 for Athe saws,between the ginning surfaces of the ribs, by simultaneously cutting orgrinding out the central portion of the webs 4 by an implement adaptedto provide absolute uniformity in the width of the spaces and in thedistance between them.

'Preferably the instrument I employ for this purpose consists of acircular gang grinder 10, mounted on, and adapted to be rotated by, ashaft 11, and having a series of grinding wheels l2, which are spacedapart exactly the same distance that separates the gin saws, and areexactly the thickness desired for grinding out the spaces 9 in which thegin sawsmust run. By applying these grinding wheels to the webs 4 andcutting through them in the manner illustrated in Figure 3, I not onlyprovide uniform spaces of proper Width, but these spaces are formed atthe exact distance apart necessary to properly t the gin saws. `Aportion of the webs 4 are left to project from either side of each ofthe ribs 2 to form the flanges '7, providing the extended ginningsurface above referred to.

By referring to Figure 4, it will be seen that the saw cylinders 8 carrythrough the lint that has been removed from the seed of the cotton inthe spaces between the ribs, or between the flanges '7, at a fairlydefinite point, which is known as the ginning point of the rib, and isindicated at 13. As previously explained, it is necessary that theginning surface of vthe rib,

especially `at the ginning point, should be very hard metal, as the sandcarried through with theV cotton would otherwise rapidly Wear away theanges 7 at the ginning vpoint and thereby widen the spaces 9 to anextent that would permit seeds, or particles of seed, to be carriedthrough with the cotton.

'I'o provide for this hardening at the ginning surface, in initialh7casting the group of ribs, the inside surface of the upper portion ofeach group, which is the side exposed to the roll box, is cast against achill plate, which results in making that portion of each group of ribs,including the webs 4 between them, extremely hard. While this hardeningpresents no difliculties to grinding the slots through the webs toprovide the spaces 9 for the gin saws, it does prevent excessive wear atthe ginning points 13, which insures the gin holding up in the qualityof its work from yearr to year.

The exact uniformity in width of the spaces 9 is required essentiallyonly in the area of the ginning points 13; but, nevertheless, obtains inmy invention, from the ginning points down tothe bottom of the ginningsurface of the ribs. Above the ginning point 13, it is customary totaper, or gradually widen the spaces to the top of the ginning surfaceto prevent broken seed, hull particles, motes and similar substancesfrom clogging the spaces abo-ve the saw teeth. The slight taper orenlargement of the space above the ginning points permits the revolvingroll of cotton in the roll box to keep the spaces wiped clear and freeof accumulation.

The arrangement of tapering spaces is illustrated as to a complete groupof ribs in Figure 5, in which the tapering portion of the spaces,extending from the ginning points 13 to the upper part of the ginningsurface of the ribs, is indicated by theY numeral 9a.

The tapering of the spaces 9 can be effected in various ways, as bygrinding or ling, although I have devised a preferred means for.simultaneously tapering all of the spaces which, however, is notinvolved in the present invention.

In( casting a group of ribs, the integral supports 3 and 5 at theopposite extremities thereof` are provided with apertures 14, and insecuring the group of ribs in position in the gin, screws are insertedin these apertures and screwed into` supporting rails 15 and 16, locatedabove and below the gin saws, respectively. Two screws in each rail aresufficient to hold rigidly in position av group of ribs, Whereas thesame number of screws are required in each end of individual ribs, ingins as at present constructed.

It will be apparent also that my inventionv simplies and reduces thecost of foundry work, in providing for casting the ribs in groups andusingA the chill plate across the entire group at theginning point.

I claim:

1. The method of manufacturing gin ribs,4 which consists in casting agroupy of equallyspaced ribs integral with supports at their oppositeextremities and with relatively thin integral129 webs connectingcorresponding end portions of, the ribs and flush with the innersurfaces thereof, and then simultaneously applying to the respectivewebs a series of grinding wheels spacedapart the distance separating thesaws of the gin and 1 5 each of which is the exact width of the workingspace for a gin saw, and grinding througln the central portion of saidwebs, throughout, the length thereof, with said grinding wheels.l

2. The method of manufacturing gin ribs,`130 which consists'in casting agroup of` equa1ly. spaced ribs integral with supports attheirLoppositeextremities and with relatively thin integral webs connectingcorresponding end portions of the ribs and flush with the inner surfacesthereof, simultaneously with the casting, chilling the inner side ofsaid portions of the ribs, including saidA webs, and then simultaneouslycuttingthrough the central portion of all of said webs, throughout thelength thereof, by means and `in, 14u a manner to provide equi-distantsaw spaces of a uniform width.

3. The method of manufacturing gin ribs, which consists in casting agroup of ribs integral with supports at their opposite extremities and145 with integral webs connecting corresponding por-l tions of the ribs,chilling a portion `of the inner side of the group including said websin the ,caste ing operation, and then simultaneously grinding, away thematerial of saidwebs to an `extent to 159 provide equi-distant sawspaces between the ribs of uniform width.

4. The method of manufacturing gin ribs, which consists in casting agroup of equallyspaced ribs integral with supports at their oppositeextremities and with relatively thin, integral Webs connectingcorresponding end portions of the ribs and flush with the inner surfacesthereof, removing the material of said webs to an extent to provideequi-distant saw spaces of uniform width, and of less width than thespaces between the ribs, and then tapering said spaces upwardly andoutwardly. t

ORVILLE MITCHELL.

